Wheat crown and root rotting fungi in Moghan area, Northwest of Iran

Wheat root and crown rot (Triticum aestivum L.) is a disease problem in many wheat producing area as well as Moghan wheat growing area, Northwest of Iran. In this study, injured plants of wheat with blighting, stunting, and death of mature plants, also necrotic lesions on seminal crown roots, sub crown internodes and crown, as well as basal stem tissue symptoms were collected from different regions of Moghan wheat growing area. Fungi associated with wheat root and crown rot were isolated and identified based on general colony morphology, the morphology of mycelia, reproductive structure and taxonomic description. Also pathogenicity of 28 selected isolates from various identified species was determined on wheat (T. aestivum L. CV. Atila 4; a common grown cultivar of wheat in Moghan area) seedlings. The results indicated that the predominant pathogens implicated in causing common root and crown rot in this study was Bipolaris sorokiniana. In addition to B. sorokiniana, Fusarium culmorum, Fusarium Pseudograminearum and Gaeumannomyces/Phiallophora complex are the most widely distributed species on wheat growing belt in Moghan area. Fusarium solani,Fusarium crookwellence, Fusarium clamidosporum, Fusarium proliferatum,Fusarium poa, Fusarium udum and Fusarium babinda are wheat root associated species of Fusarium ascertained during our investigation. Pathogenicity test revealed that B. sorokiniana, F. culmorum, F. graminearum, F. crookwellence, F. udum and Gaeumannomyces/Phiallophora complex are active pathogens and others are saprophytes, which are also involved in the destruction of root tissues, without being the cause of injury. Key words: Wheat, common root and crown rot, Bipolaris sorokiniana, Fusariumsp., Gaeumannomyces/ Phiallophora complex.